Anaemia - Haemolytic Anaemia - Autoimmune Haemolytic Anaemia (AIHA)

Question 1

What is AIHA?

Answer 1

Autoimmune Haemolytic Anaemia - antibodies are created against the patient’s RBCs, leading to their destruction.

Question 2

What are the types of AIHA? (2).

Answer 2

Based on the temperature of the functioning of autoantibodies :-

1. Warm-Type AIHA (commoner).
2. Cold-Type AIHA.

Question 3

What is Warm-Type AIHA?

Answer 3

Extravascular (splenic) haemolysis occurs at normal or above normal temperatures by IgG antibodies.

Question 4

Aetiology of Warm-Type AIHA.

Answer 4

1. Idiopathic usually.
2. Autoimmune Disease e.g. SLE.
3. Neoplasia e.g. Lymphoma, CLL.
4. Drugs e.g. Methyldopa.

Question 5

What is Cold-Type AIHA?

Answer 5

Cold-Agglutinin Disease - agglutination (and consequent destruction) at lower temperatures; intravascular haemolysis mediated by Complement and IgM.

Question 6

Aetiology of Cold-Type AIHA (4).

Answer 6

Secondary to Other Conditions e.g. :

1. Lymphoma.
2. Leukaemia.
3. SLE.
4. Infections e.g. Mycoplasma, EBV, CMV, HIV.

Question 7

Clinical Presentation of Cold-Type AIHA (2).

Answer 7

1. Raynaud’s.

2. Acrocyanosis.

Question 8

Investigations of AIHA (3).

Answer 8

1. Bloods : Anaemia, Reticulocytosis, Low Haptoglobin, Raised LDH and Indirect Bilirubin.
2. Blood Film : Spherocytes and Reticulocytes.
3. Positive Coombs’ (Direct Antiglobulin) Test.

Question 9

What is Coombs Test?

Answer 9

Antibodies are used against the autoantibodies to test for their presence.

Question 10

Management of AIHA.

Answer 10

1. Blood Transfusions.
2. Prednisolone (Steroids).
3. Rituximab (Monoclonal Antibody against B cells).
4. Splenectomy.